0-1Knapsack.py

def knapSack(W, wt, val, n):
    '''
    Returns the maximum value that can be put in a knapsack of
    capacity W
    '''
    # Base Case
    if n == 0 or W == 0:
        return 0

    # If weight of the nth item is more than Knapsack of capacity
    # W, then this item cannot be included in the optimal solution
    if (wt[n - 1] > W):
        return knapSack(W, wt, val, n - 1)

    # return the maximum of two cases:
    # (1) nth item included
    # (2) not included
    else:
        return max(val[n - 1] + knapSack(W - wt[n - 1], wt, val, n - 1),
                   knapSack(W, wt, val, n - 1))


# To test above function
val = [60, 100, 120]
wt = [10, 20, 30]
W = 50
n = len(val)
print(knapSack(W, wt, val, n))